*2.2. GC-MS Analysis of Melissa Essential Oil*

*2.2. GC-MS Analysis of Melissa Essential Oil* The chromatogram of Melissa essential oil is shown in Figure 2. The main compounds detected in MOEO were 2,6-octadienal, 3,7-dimethyl (20.40%), citral (19.64%), caryophyllene (9.28%), geranyl acetate (7.33%), caryophyllene oxide (6.85%), citronellal (6.58%), and linalool (6.00%) (Table 1). As per Sorensen's research [15], the primary constituents of *M. officinalis* obtained through laboratory distillation of verified plant material are the isomers of citral, geranial, and neral. Previous studies have reported that the essential oil of lemon balm contains citronellol and linalool as their primary chemical constituents [15,16]. Park and Lee [17] reported that the major compound of essential oil in lemon was 2,6-octadienal and 3,7-dimethyl-. The varied chemical components in the liter-The chromatogram of Melissa essential oil is shown in Figure 2. The main compounds detected in MOEO were 2,6-octadienal, 3,7-dimethyl (20.40%), citral (19.64%), caryophyllene (9.28%), geranyl acetate (7.33%), caryophyllene oxide (6.85%), citronellal (6.58%), and linalool (6.00%) (Table 1). As per Sorensen's research [15], the primary constituents of *M. officinalis* obtained through laboratory distillation of verified plant material are the isomers of citral, geranial, and neral. Previous studies have reported that the essential oil of lemon balm contains citronellol and linalool as their primary chemical constituents [15,16]. Park and Lee [17] reported that the major compound of essential oil in lemon was 2,6 octadienal and 3,7-dimethyl-. The varied chemical components in the literature could be attributed to several factors influencing the chemical diversity of essential oils, such as light, precipitation, growth location, and soil [18].

oils, such as light, precipitation, growth location, and soil [18].

**Table 1.** Primary components detected in Melissa essential oil.

ature could be attributed to several factors influencing the chemical diversity of essential

**No. NAME R. Time Composition %**

 Citral 21.495 19.64 Caryophyllene 27.183 9.28 Geranyl acetate 25.788 7.33 Caryophyllene oxide 33.622 6.85 Citronellal 15.68 6.58 Linalool 13.413 6.00

*2.3. Thickness* **Table 1.** Primary components detected in Melissa essential oil.


#### **Table 2.** Thickness, mechanical, and barrier properties of edible film samples loaded with MOEO. *2.3. Thickness*

0.05).

*2.4. Mechanical Attributes*

**Film Samples Thickness (mm) Elongation at Break (%) Tensile Strength (MPa) Water Vapor Permeability (g mm/m<sup>2</sup> h kPa) Moisture Content (%)** B 0.061 ± 0.005 <sup>a</sup> 27.36 ± 1.94 <sup>a</sup> 8.12 ± 0.68 <sup>a</sup> 0.676 ± 0.02 <sup>a</sup> 29.92 ± 0.53 <sup>a</sup> PC20 0.068 ± 0.005 ab 30.24 ± 2.23 bc 3.48 ± 0.11 <sup>b</sup> 0.569 ± 0.04 <sup>b</sup> 28.30 ± 0.57 <sup>b</sup> PC30 0.072 ± 0.008 <sup>b</sup> 34.97 ± 3.76 cd 2.37 ± 0.21 <sup>c</sup> 0.536± 0.05 <sup>b</sup> 26.55 ± 0.23 <sup>c</sup> PC40 0.073 ± 0.006 <sup>b</sup> 36.29 ± 2.80 <sup>d</sup> 1.25 ± 0.16 <sup>d</sup> 0.327 ± 0.01 <sup>c</sup> 25.16 ± 0.83 <sup>c</sup> The values with different letters (a, b, c, and d) inside a column indicate significant differences (*p* < Table 2 presents the results that were obtained for the average thickness of the edible film samples. The thickness values varied between 0.061 and 0.073 mm by the incorporation of MOEO. Control film (B) had the lowest value of thickness (0.061 mm); however, the highest value (0.073 mm) was observed in PC40 with a maximum concentration (0.2%) of MOEO. The results demonstrate that incorporating MOEO in pectin–collagen-based hydrogel films had a significant (*p* > 0.05) effect on the resultant film thickness. The observed increase in thickness may be attributed to the incorporation of oil into the film matrix, which consequently led to the generation of microdroplets owing to the oil's hydrophobic properties [19]. In our prior research, the incorporation of ginger essential oil had an impact on the thickness of hydrogel films composed of chitosan and porphyran [20].

> The mechanical properties of biopolymer films are commonly evaluated through the measurement of TS and EAB. The mechanical resistance of a film is attributed to cohesive forces between chains, which is represented by its tensile strength. On the other hand, the flexibility of a film, or its capacity to elongate before breaking, is evaluated through its elongation at break. The concurrent study of tensile strength and elongation at break is


**Table 2.** Thickness, mechanical, and barrier properties of edible film samples loaded with MOEO.

The values with different letters (a, b, c, and d) inside a column indicate significant differences (*p* < 0.05).
